Lasiosphaeris hirsuta

Lasiosphaeris hirsuta is a fungal species categorized within the class Sordariomycetes. While often identified as a saprotrophic fungus primarily colonizing decaying wood, it can act as a pathogen affecting weakened, stressed, or structurally damaged plants, particularly within orchards and forest nurseries.

The fungus targets various woody species, attacking the bark and internal xylem tissues. The pathogen typically enters the host through wounds, pruning cuts, or environmental lesions, utilizing the nutrient-rich decaying material to establish mycelial networks that degrade healthy cells.

Symptoms are identified by the presence of small, dark perithecia covered in distinctive hair-like structures, which cluster on the surface of the infected bark. Affected plants exhibit signs of localized necrosis, cortical decay, and a noticeable decline in overall vigor, which can lead to branch dieback.

Optimal conditions for development include high humidity, stagnant airflow, and moderate temperatures. The fungus propagates through airborne spores and water splashing, which ensures rapid colonization of susceptible plant parts when moisture levels are sustained for prolonged periods.

Economic damage is mitigated through rigorous integrated pest management strategies. Control measures should include:

• pruning and disposing of dead or infected branches;
• maintaining plant health to increase resistance;
• applying copper-based fungicides to large wounds;
• ensuring adequate aeration to reduce surface moisture.